SG189003A1

SG189003A1 - Utilization of process heat by-product

Info

Publication number: SG189003A1
Application number: SG2013019328A
Authority: SG
Inventors: John David Penton; Leonore R Rouse; Jerry M Rovner
Original assignee: Chevron Usa Inc
Priority date: 2010-10-06
Filing date: 2011-10-06
Publication date: 2013-05-31
Also published as: WO2012048132A3; US20120085095A1; CA2813420A1; SG188593A1; US20120085097A1; KR20140000219A; KR20130099959A; AU2011311963A1; CA2812796A1; WO2012048135A2; ZA201301931B; WO2012048132A2; WO2012048135A3; AU2011311966A1

Abstract

Heat recovery systems and methods for producing electrical and/or mechanical power from a process heat by-product are provided. Sources of process heat by-product include hot flue gas streams, high temperature reactors, steam generators, gas turbines, diesel generators, and process columns. Heat recovery systems and methods include a process heat by-product stream for indirectly heating a working fluid of an organic Rankine cycle. The organic Rankine cycle includes a heat exchanger, a turbine-generator system for producing power, a condenser heat exchanger, and a pump for recirculating the working fluid to the heat exchanger.

Description

UTHLIZATION OF PROCESS HEAT BY-PRODUCT

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to U.S. Provisional Patent Application

No. 61/390,397, cotitled "Utilizing Waste Heat From Refinery Operations” and filed on

October 6, 2010, in the name of John David Penton ef of, the entire disclosure of which is hereby fully incorporated herein by reference.

TECHNICAL FIELD

[00621 The present application generally relates to heat recovery and utilization.

More particularly, the present application relates fo the utilization of process heat by-product to generate electricity and/or mechanical power.

BACKGROUND

[0003] {Objective and regulations surrounding carbon and energy usage has raised the importance of designing and retrofitting existing processes for higher levels of energy efficiency. The primary driving forces are the need to reduce greenhouse gas emissions or local pollution, reducing the energy investment requirement, and best utilizing existing supply capacities to tmprove the access to energy. To increase the energy efficiency of a process, it is necessary to improve the utibization of the energy inputted and reduce the energy wasted to the atmosphere. One coromon area of wasted energy is in the heat exhausted from sources within the oil and gas industry, from processes such as fluid catalytic cracking regenerator column overheads, steam generator exhaust, turbine exhaust, and other flue gas

SOUTCES.

[004] Currently, methods for recovering higher ifemperature waste heat include witlizing the heat for preheat of other processes or for the production of steam. This heat can he utilized in heat recovery steam generators or heat exchangers. One such avenue of mereasing the energy efficiency of a process is to utilize the low temperature “waste heat”, typically below S00 degrees Fahrenheit (°F), for power generation or mechanical power. In geothermal applications and reciprocating engines, an organic Rankine cycle system is utilized for the conversion of heat to power. The exhaust gas or brine exchanges with a working fluid to produce the desired power output. However, there are curently several drawbacks with utilization of an organic Rankine cycle in a refining process or various flue gas exhaust systems. The current technologies have been unable to reach the necessary efficiencies at the low teroperature ranges of these process streams. Additionally, current technologies have been unable to incorporate appropriate exchanger technology that would sufficiently decrease fouling and reliability risks in a process with volatile flowrates and temperatures. There are also difficulties with structurally integrating the technelogy within a much more coraplex process setting when corgpared to the current installations.

[0005] Therefore, a need exists for a process to effectively and efficiently capture and convert this waste heat to a useful energy source.

SUMMARY

[0006] The present invention is directed to processes for heat recovery from process heat by-product, wherein such heat recovery is realized by channeling thermal energy from a process heat by-product siream to an organic Rankine cycle—from which electricity can be derived through a turbine-driven generator. The present invention is also directed fo systems for implementing such processes.

[0067] In one aspect of the invention, a process for indirectly utilizing process heat by-prodoct from refinery operations includes three sub-processes that occur simultaneously.

The first and second sub-processes are linked via a first heater, and the second and third sub- processes are Hnked via a second heater. In the first sub-process, a process heat by-product stream is directed to the first heater and is utihized to heat a first working {oid stream to produce a cooled by-product stream and a heated working fluid stream. The cooled by- product strearn is then exhausted to atmosphere. In some instances, the process heat by- product stream includes flue gas from a {hud catalytic cracking unit or recovered heat from a high temperature reactor, such as a fired heater, incinerator, hydrotreater, catalytic reformer, ot isomerization unit. In the second sub-process, the first working fluid stream is heated by the process heat by-product siream in the first heater to form a first heated working fluid stream. The first heated working {had stream is direcled to the second heater, and is utilized to heat a working hud stream of an organic Rankine cycle to produce a cooled working fluid strearn and a second heated working thud stream. The cooled working fluid stream 1s then passed through a pump to form the first working fluid strearn. In the third sub-process, the working fluid stream of the organic Rankine cycle is heated to form the second heated working fluid streara. In certain aspects, the second heated working fluid stream is vaporized. The second heated working fluid stream 1s passed through a turbine-generator set to form an expanded working fluid stream and produce electricity and/or mechanical power.

The expanded working fluid stream is then directed fo another heat exchanger to form a condensed working fluid stream. The condensed working fhuid stream is then passed through a pump to form the working thud stream that enters the second heater.

[008] In another aspect of the invention, a process for indirectly utilizing waste heat by-product includes three sub-processes that occur simultancously. The first and second sub- processes are linked via a first heater, and the second and third sub-processes are linked via a second heater. In the first sub-process, a waste heat by-product stream is directed to the first heater and is utilized to heat a first working fluid stream to produce a cooled by-product stream and a heated working fluid stream. The cooled by-product stream 1s then exhausted to atmosphere. In certain aspects, the cooled by-product stream is directed to an incinerator, a scrubber, or a stack prior to being exhausted to the atmosphere. In certain aspects, the waste heat by-product stream includes waste heat from a steam generator, gas turbine, or diesel generator. In the second sub-process, the first working fluid stream is heated by the waste heat by-product stream in the first heater to form a first heated working fluid stream. The first heated working fluid stream is divected to the second heater, and is utilized to heat a working fluid stream of an organic Rankine cycle to produce a cooled working fluid stream and a second heated working fluid stream. The cooled working fluid stream is then passed through a pump to form the first working fluid stream. In the third sub-process, the working fluid stream of the organic Rankine cycle is heated to form the second heated working fluid stream. In certain aspects, the second heated working fluid strearn is vaporized. The second heated working uid stream is passed through a turbine-generator set to form an expanded working hud stream: and produce electricity and/or mechanical power. The expanded working fluid stream is then directed to another heat exchanger to forma a condensed working fluid stream. The condensed working thud stream is then passed through a pump to form the working {hud stream that enters the second heater, [00091 In yet another aspect of the invention, a system for utilizing a heat by-product mchudes a process heat by-product stream and an organic Rankine cycle subsystem. In certain aspects, the organic Rankine cycle subsystem includes a heat exchanger in thermal communication with the heat by-product stream, an organic Rankine cycle flow line having a working fluid, whereby the flow line is in thermal communication with the heat exchanger, and whereby the heat exchanger transfers thermal energy from the heat by-product stream to the working {hud so as to heat the working fluid to form a heated working fluid, a torbine- based generator for generating electricity and/or mechanical power from the heated working

{hud passing through, one or more condensers for condensing the heated working fluid to form a condensed working hud, and a purop for pumping the condensed working fluid to a higher pressure to form the working fluid that enters the heat exchanger.

[0010] The features of the present invention will be readily apparent to those skilled in the art upon a reading of the description of the preferred embodiments that follows.

BRIEF DESCRIPTION OF THE BRAWINGS

[0011 For a more complete understanding of the exemplary embodiments of the present vention and the advantages thereof, reference is now made to the following description in conjunction with the accompanying drawings, which are briefly described as follows.

[0012] FIG. 1 is a schematic diagram of a heat recovery system for utilization of waste heat from a fluid catalytic cracking unit, according to an exemplary embodiment.

[013] FIG. 2 is a schematic diagram of a heat recovery system for utilization of waste heat from a fluid catalytic cracking unit, according to another exemplary embodiment.

[0014] FIG. 3 is a schematic diagram of a heat recovery systema for utilization of waste heat from a fluid catalytic cracking unit, according to yet another exemplary embodiment.

[0015] FIG. 4 is a schematic diagram of a heat recovery system for utilization of waste heat from a thud catalytic cracking uni, according to yet another exemplary embodiment.

[16] FIG. 5 is a schematic diagram of a heat recovery system for utilization of process heat by-product from a fired heater unit, according to an exemplary embodiment.

[0017] FIG. 6 4s a schematic diagram of a heat recovery system for utilization of process heat by-product from a fired heater unit, according to another exemplary embodiment.

[0018] FIG. 7 is a schematic diagram of a heat recovery system for utilization of process heat by-product from a fired heater unit, according to yet another exemplary embodiment. [O0191 FIG. § is a schematic diagram of a heat recovery systema for utilization of process heat by-product from a fired heater omit, according to vet another exemplary embodiment. [00201 FIG. 9 is a schematic diagram of a heat recovery system for utihization of an exhaust gas stream {rom a steam generator unit, according to an exeroplary embodiment.

[0021] FIG. 10 is a schematic diagram of a heat recovery system for utilization of an exhaust gas stream {rom a steam generator unit, according to another exemplary embodiment.

[0022] FIG. 11 1s a schematic diagram of a heat recovery system for utilization of an exhaust gas stream from a steam generator unit, according to yet another exemplary embodiment. [00231 FIG. 12 is a schematic diagram of a heat recovery system for utilization of an exhaust gas stream from a stearn generator unit, according to yet another exemplary embodiment.

[0024] FIG. 13 is a schematic diagram of a heat recovery system for utilization of an exhaust gas stream {rom a gas turbine unit, according fo an exemplary erobodiment.

[0025] FIG. 14 1s a schematic diagram of a heat recovery system for utilization of an exhaust gas stream {rom a gas turbine unit, according to another exemplary embodiment.

[026] FIG. 15 is a schematic diagram of a heat recovery system for utilization of an exhaust gas stream from a gas turbine unit, according to vet another exemplary embodiment. [00273 FIG. 16 1s a schematic diagram of a heat recovery system for utilization of an exhaust gas stream from a gas turbine unit, according to yet another exemplary embodiment.

[0028] FIG. 17 1s a schematic diagram of a heat recovery system for utilization of a process heat stream, according to an exemplary embodiment.

[029] FIG. 18 is a schematic diagram of a heat recovery system for ulilization of a process heat stream, according to another exemplary embodiment,

[0030] FIG. 19 1s a schematic diagram of a heat recovery system for utilization of a process heat stream, according to yet another exemplary embodiment.

[0031] FIG. 20 is a schematic diagram of a heat recovery system for utilization of a process heat stream, according to yet another exemplary embodiment.

DETAILED DESCRIPTION

[00323 Hlustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. One of ordinary skill in the art will appreciate that in the development of any such actual embodiment, numerous implementation-specific decisions roust be made fo achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[0033] The present invention may be better understood by reading the following description of non-limitative erobodiments with reference to the attached drawmgs wherein like paris of cach of the figures are identified by the same reference characters. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, for example, a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase 1s intended to have a special meaning, {or instance, a roeaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase. Moreover, various streams or conditions may be referred to with terms such as "hot,” “cold,” "cooled, "warm," etc., or other hike terminology. Those skilled in the art will recognize that such terms reflect conditions relative to another process stream, not an absolute measurement of any particular temperature,

[0034] FIG. 1 shows a direct heat recovery system 100 for utilization of a flue gas stream 102 from a fluid catalytic cracking regenerator anit 101. Generally, the flue gas stream 102 is a high temperature heat stream that is generated by the combustion of coke in the fluid catalytic cracking regenerator unit 101. Fo certain embodiments, the flue gas stream 102 has a temperature in the range of from about 1100 to about 1800 °F. In certain exemplary embodiments, when the combustion of coke is complete, at least a portion 192a of the flue gas stream 102 enters a wasic heat steam generator 103. A botler feed water stream 14 also enters the waste heat steam generator 103, and heat {rom the flue gas stream 102 is utilized to heat the boiler feed water stream 104 to produce a steam stream 105. In certain embodiments, the waste heat steam generator 103 generaies steam at pressures in the range of from about 15 fo about 1100 pound-force per square inch gauge (psig). A reduced heat flue gas stream 106 then exits the waste heat steam generator 103 and enters an electrostatic precipitator 107, which removes any catalyst fines 108 present in the reduced heat flue gas stream 106 to produce a reduced fines flue gas stream 109. In certain exemplary embodiments, the reduced fines flue gas strearn 109 has a teroperature in the range of from about 350 to about 80{ °F.

[0035] In certain embodiments, when the combustion of coke 1s incomplete and the flue gas stream 102 contains significant amounts of carbon monoxide, at least a portion 102b of the flue gas stream 102 enters a carbon monoxide botler 110. A fuel stream 111 and an air stream 112 also enter the boiler 110 to combust the carbon monoxide in the flue gas stream 102. A boiler feed water stream 114 also enters ihe boiler 110, and heat from the combustion process and the flue gas stream 102 is utilized to beat the boiler feed water stream 114 {o produce a steam stream 115. In certain embodiments, the boiler 110 operates at a pressure in the range of from about 15 to about 1100 psig. A reduced heat {loc gas stream 116 then exits the boiler 110 and enters an electrostatic precipitator 117 fo remove any catalyst fines 11§ present in the reduced heat flue gas stream 116 fo produce a reduced fines flue gas stream 119. In certam embodiments, the reduced fines flue gas stream 119 has a temperature in the range of from about 350 to about 800 °F.

[0036] In certain embodimenis, a portion 102a of the flue gas stream 102 can be routed through the waste heat steam generator 103, and the resulting reduced fines flue gas sirearn 109 can be combined with a remaimder portion 102¢ of the flue gas stream 102 afterwards prior to entering a heat exchanger 120. The heat exchanger 120 is a part of the organic Rankine cycle. The heat exchanger 120 may be any type of heat exchanger capable of transferring heat from one {hud stream to another fluid stream. Suitable examples of heat exchangers include, but are not limited to, heaters, vaporizers, economizers, and other heat recovery heat exchangers. For example, the heat exchanger 120 may be a shell-and-tube heat exchanger, a plate-fin-tube coil type of exchanger, a bare tube or finned tube bundle, a welded plate heat exchanger, and the like. Thus, the present invention should not be considered as limited to any particular type of heat cxchanger unless such limitations are expressly set forth in the appended claims. fn cerfain other embodiments, the flue gas stream 112 can be entirely routed through the waste heat steam generator 103. In certain alternative embodiments, a portion 102b of the flue gas stream 102 can be routed through the through the botler 110, and the resulting reduced fines flue gas stream 119 can be combined with the remainder portion 102¢ of the flue gas stream 102 afterwards prior to entering the heat exchanger 120. In certain other embodiments, the flue gas stream 102 can be entirely routed through the boiler 110. In yet other embodiments, a {first portion 102a of the flue gas stream 102 can be routed through the waste heat sicam generator 103, a second portion 102b of the flue gas stream 102 can be routed through the boiler 114, and the resulting reduced fines flue gas streams 109, 119 can be combined with a third portion 102¢ of the flue gas stream 102 afterwards prior to entering the heat exchanger 120. In certain other embodiments, the flue gas stream 102 can directly enter heat exchanger 120. One having ordinary skill in the art will recognize that the flue gas stream 102 can be treated any number of ways and in any combination to produce an input thie gas stream 125 prior to entering the heat exchanger 120.

[0037] At least a portion 125a of the input flue gas stream 125 is then utilized to heat a working thud stream [26 m the heat exchanger 120. The portion 125a of the input flue gas stream 125 thermally contacts the working fluid stream 126 to transfer heat to the working fluid stream 126. As used herein, the phrase “thermally contact” generally refers to the exchange of energy through the process of heat, and does not imply physical mixing or divect physical contact of the materials. In certain excroplary embodiments, the working fluid stream 126 includes any working fluid suitable for use jn an organic Rankine cycle. The portion 125a of the input flue gas stream 125 and the working (had stream 126 enter the heat exchanger 120 to produce a heated working fluid stream 128 and a reduced heat flue gas stream 129. In certain exemplary embodiments, the working fluid stream 126 has a temperature in the range of from about 80 to about 150 °F. {n certain excroplary embodiments, the heated working fluid stream 128 has a temperature in the range of from about 160 to about 450 °F. In certain exemplary embodiments, the heated working fluid stream 128 is vaporized. In certain exemplary embodiments, the heated working fluid stream 128 is vaporized within a supercritical process, with conditions at a temperature and pressure above the critical point for the heated working fluid stream 128. In certain exemplary embodiments, the heated working fluid stream 1285 is superheated. In certain exemplary embodiments, the working fluid stream 126 enters as a high pressure quid and the heated working fluid stream 128 exits as a superheated vapor. In certain exemplary embodiments, the reduced heat flue gas stream 129 has a temperature in the range of from about 300 to about 750 °F. In certain embodiments, the reduced heat flue gas stream 129 is cooled to a temperature just above its dew point. The reduced heat flue gas stream 129 can then be vented to the atmosphere. In certain exemplary embodiments, a portion 125b of the input flue gas stream 125 is diverted through a bypass valve 130 and then combined with the reduced heat flue gas stream 129 to produce an exhaust thie gas siream 131 to be vented to the atmosphere. In certain exemplary embodiments, the exhaust flue gas stream 131 has a temperature in the range of from about 300 °F to about 800 °F. In certain exemplary embodiments, the entire portion 125a of the input flue gas stream 125 is directed through the heat exchanger 120, and is exhausted to the atmosphere af a teroperature of about 300 °F.

[038] At least a portion 128a of the heated working {hid stream 128 is then directed te a turbine-generator system 150, which is a part of the organic Rankine cycle. For purposes of the present application, the term “turbine” will be understood to include both turbines and expanders or any device wherein useful work is generated by expanding a high pressure gas within the device. The portion 128a of the heated working fluid streara 128 is expanded on the turbine-generator system 150 to produce an expanded working fluid stream 151 and generate power. In certam exemplary embodiments, the expanded working {laid stream 151 has a temperature in the range of from about 80 to about 440 °F. In certain ernbodiments, the turbine-generator system 150 generates electricity or electrical power. In certain other embodiments, the turbine-generator system 150 generates mechanical power. In certain embodiments, a portion 128b of the heated working fhud stream 128 is diverted through a bypass valve 152 and then combined with the expanded working fluid stream 151 to produce an intermediate working fluid stream 155. Tn certain exemplary embodiments, the mtermediate working tloid stream 155 has a temperatare in the range of from about 85 to about 445 °F.

[0039] The intermediate working fluid stream 155 is then directed to one or more air- cooled condensers 157. The air-cooled condensers 157 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two air-cooled condensers 157 in series. Suitable examples of air-cooled condensers include, but are not hmited to, air coolers and evaporative coolers. In certain exemplary embodiments, each of the air-cooled condensers 157 1s controlled by a variable frequency drive 158. The air-cooled condensers 157 cool the intermediate working fluid stream 155 to form a condensed working fluid strearn 159. in certain exemplary embodiments, the condensed working fluid stream 159 has a temperature in the range of from about 80 to about 158 °F. The condensed working fluid stream 159 is then directed to a pump 160. The pump 160 is a part of the organic

Rankine cycle. The purap 160 may be any type of coramercially available pump sufficient to meet the pumpmg requirements of the systems disclosed herein. In certain exemplary embodiments, the pomp 160 is controlled by a vanable frequency drive 161. The pump 160 returns the condensed working fluid stream 159 to a higher pressure fo produce the working fluid stream 126 that is directed to the heat exchanger 120. [00407 FIG. 2 shows a direct heat recovery system 200 according fo another exemplary embodiment. The heat recovery system 200 is the same as that described above with regard {0 heat recovery system 100, except as specifically stated below. For the sake of brevity, the simularifics will not be repeated heremmbelow. Referring now to FIG. 2, the mtermediate working {hid stream 155 is then directed to one or more water-cooled condensers 257. The water-cooled condensers 257 are a part of the organic Rankine cyele.

In certain exeraplary embodiments, the organic Rankine cycle includes two water-cooled condensers 257 in series. The water-cooled condensers 257 cool the intermediate working fluid streamn 155 to form a condensed working fluid stream 259. in certain exemplary embodiments, the condensed working fluid stream 259 has a temperature in the range of from about 8&0 to about 150 °F. The condensed working fluid stream 2359 is then direcied to the pump 160 and is returned to a higher pressure to produce the working fluid stream 126 that is directed to the heat exchanger 120.

[0041] FIG. 3 shows an indirect heat recovery system 300 for utilization of an input flue gas stream 325. The input flue gas stream 325 is the same as that described above with regard to input fluc gas streara 125, and for the sake of brevity, the similarities will not be repeated herembelow. Referring now to FIG. 3, at least a portion 325a of the input flue gas stream 325 is ulibized to heat a working thud stream 326 in a heat exchanger 320. The portion 325a of the input flue gas stream 3235 thermally contacts the working fluid stream 326 and transfers heat to the working fluid stream 326. Suitable examples of the working thud stream 326 include, but are not Himited to, water, glycols, therminol {luids, alkanes, alkenes, chlorofluorocarbons, hydrofloorocarbons, carbon dioxide (CO2), refrigerants, and mixtures of other hydrocarbon components. The portion 325a of the input flue gas stream 325 and the working fluid stream 326 enter the heat exchanger 320 to produce a heated working fluid stream 328 and a reduced heat flue gas stream 329. In certain exemplary embodiments, the working fluid stream 326 has a temperature in the range of from about 85 to about 160 °F. In certain exeroplary embodiments, the heated working fluid stream 328 bas a temperature in the range of from about 165 to about 455 °F. In certain exemplary embodiments, the reduced heat flue gas stream 329 has a temperature in the range of from about 300 to about 750 °F. In certain erobodiments, the reduced heat flue gas stream 329 is cooled to a temperature just above its dew point. The reduced heat flue gas stream 329 can then be vented to the atmosphere. In certain exemplary embodiments, a portion 325b of the input flue gas stream 325 is diverted through a bypass valve 330 and then combined with the reduced heat flue gas strearn 329 to produce an exhaust flue gas stream 331 to be vented to the atmosphere. In certain exemplary embodiments, the exhaust flae gas stream 331 has a temperature in the range of {rom about 300 to about 800 °F. In certain exemplary embodiments, the input {hie gas stream 325 is entirely directed through the heat exchanger 320), and is exhausted to the atmosphere at a temperature of about 300 °F.

[042] A portion 328a of the heated working {luid stream 328 enters a heat exchanger 335 to heat a working fluid stream 336 to produce a heated working fluid stream 337 and a reduced heat working fluid stream 338. The portion 328a of the heated working fluid stream 328 thermally contacts the working fluid stream 336 and transfers heat fo the working fTuid stream 336. lu certain exemplary embodiments, the working fluid stream 336 includes any working fluid suitable for use in an organic Rankine cycle. In certain exemplary embodiments, the working {huid stream 336 has a temperature in the range of {from about 80 to about 150 °F. In certain exemplary embodiments, the heated working fluid stream 337 has a temperature in the range of from about 160 to about 450 °F. in certain exemplary embodiments, the heated working fluid stream 337 is vaporized. In certain exemplary embodiments, the heated working fluid siream 337 is vaporized within a supercritical process. In certain excroplary embodiments, the heated working fuid stream 337 is superheated. In certain exemplary embodirnents, the reduced heat working fluid stream 338 has a temperature in the range of from about 85 to about 155 °F. In certain embodiments, a portion 3280 of the heated working fluid stream 328 is diverted through a bypass valve 339 and then combined with the reduced heat working fluid stream 33% to produce an termediate working thud stream 340. In certain exeroplary embodiments, the miermediate working fluid stream 340 has a temperature in the range of from about 83 to about 160 °F.

The intermediate working fluid stream 340 is then directed to a purop 342. Io certain exemplary ernbodiments, the pump 342 is controlled by a variable frequency drive 343. The pump 342 returns the intermediate workmg fluid stream 340 to produce the working fluid stream 326 that enters the heat exchanger 320.

[0043] At least a portion 337a of the heated working fluid stream 337 is then directed to a turbine-generator system 350, which is a part of the organic Rankine cycle. The portion 337a of the heated working fluid stream 337 is expanded in the turbine-generator system 350 te produce an expanded working fhuid stream 331 and generate power. In certain exemplary embodiments, the expanded working thud stream 351 has a temperature in the range of from about 80 to about 440 °F. In certain embodiments, the turbine-generator system 350 generates electricity or electrical power. In certain other embodiments, the turbine-generator system 350 generates mechanical power. In certain embodiments, a portion 337b of the heated working fluid stream 337 1s diverted through a bypass valve 352 and then combined with the expanded working fluid stream 351 to produce an intermediate working floid stream 355. In certain exemplary embodiments, the intermediate working fluid stream 355 has a temperature in the range of from about 85 fo about 445 °F.

[3044] The intermediate working {hud stream 355 is then directed to one or more air- cooled condensers 357. The air-cooled condensers 357 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two air-cooled condensers 357 in series. In certain exemplary cmbodiments, cach of the air-cooled condensers 357 1s controlled by a variable frequency drive 358. The air-cooled condensers 357 cool the intermoediate working fluid stream 355 to form a condensed working fhuid stream 359. In certain exemplary embodiments, the condensed working fluid siveam 359 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid strearn 359 is then directed to a pump 360. The pump 360 is a part of the organic Rankine cycle. In certain exemplary embodiments, the pump 360 is controlled by a variable frequency drive 361. The pump 360 returns the condensed working fluid stream 35% to a higher pressure to produce the working fluid stream 336 that is directed to the heat exchanger 335.

[0345] FIG. 4 shows an indirect heat recovery system 400 according to another exemplary embodiment. The heat recovery system 400 is the same as that described above with regard to heat recovery system 300, except as specifically stated below. For the sake of brevity, the similarities will not be repeated herembelow. Referrmg now to FIG. 4, the intermediate working fluid siream 355 is directed to one or more water-cooled condensers 457. The water-cooled condensers 457 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two water-cooled condensers 457 in series. The water-cooled condensers 457 cool the intermediate working fluid stream 355 to form a condensed working fluid stream 459. In certain exemplary embodiments, the condensed working fluid stream 439 has a teroperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 459 is then directed to the pump 360 and is returned to a higher pressure to produce the working fluid stream 336 that is directed to the heat exchanger 335.

[0046] Referring now to FIG. 5, a direct heat recovery system 500 for utilizing heat from a high temperature reactor, such as a convection section of a fired heater 302, is shown.

In certain embodiments, the high temperature reactor is an incinerator, hydrotreater, catalytic reformer, or isomerization unit. Generally, the fired heater 302 1s used m a refinery to heat a feedstock stream 503 going to a refinery unit. Suitable examples of refinery units include, but are not limited to, crude distillation units and vacuum distillation units. In certain embodiments, a fuel strearn 505 and an air stream 506 enter a burner section of the fired heater 502 and heat the feedstock stream 503 to produce a heated feedstock stream 507. In certain embodiments, the heat from the resulting flue gas stream 308 can then be used to heat a steam stream S09 to produce a saturated or superheated steam stream 510 and a fluc gas stream S11. In certam exemplary embodiments, the flue gas stream 511 has a teroperature in the range of from about 350 to about 800 °F.

[0047] The flue gas stream 511 can then be utibized to heat a portion 512a of a working fluid stream 512. In certain exemplary embodiments, the working fluid stream 512 mclodes any working fluid suitable for use in an organic Rankine cycle. The flue gas stream 511 and the portion 512a of the working fluid stream 512 enter a beater 513 to produce a heated working fluid stream 514 and a reduced heat flue gas stream 515. The flue gas stream 511 thermally contacts the working fluid stream 512 and transfers heat to the working fluid stream 512. The heater 513 is a part of the organic Rankine cycle, and can be integrated into the convection section of the fired heater 502. In certain exemplary embodiments, the portion 512a of the working fluid stream 512 has a temperature in the range of from about 80 to about 150 °F. In certain exemplary embodiments, the heated working thud stream 514 has a temperature in the range of from about 160 to about 450 °F. In certain excraplary embodiments, the heated working fluid stream 514 15 vaporized. In certain exemplary embodiments, the heated workmg {hud streams 514 is vaporized within a supercritical process. In certain excraplary embodiments, the heated working fluid stream 514 is superheated. In certain exemplary erobodiments, the reduced heat flue gas stream 515 has a temperature in the range of from about 300 to about 750 °F. In certam embodiments, the reduced heat flue gas stream 515 has a temperature of about 300 °F. The reduced heat flue gas stream 515 can then be venied to the atmosphere. In certain exemplary embodiments, a portion 512b of the working fluid stream 512 is diverted through a bypass valve 517 and then combined with the heated working hud stream 514 to produce a working {hud stream 518.

In certain exemplary embodiments, the working fluid stream 518 has a temperature in the range of from about 1355 to about 455 °F. In certain exemplary embodiments, the working fluid stream 512 is entirely directed through the heater 513.

[048] At least a portion 518a of the working fluid stream 518 is then directed to a turbine-generator system 550 where the portion 518a of the working fluid stream 518 is expanded to produce an expanded working thud stream 551 and generate power. In certain exemplary embodiments, the expanded working fluid stream 551 has a temperature in the range of from about 80 to about 440 °F. In certain embodiments, the turbine-genecrator system S50 generates electricity or electrical power. In certain other embodiments, the tarbine-generator system 550 generates mechanical power. In certam embodiments, a portion 518b of the working floid stream 518 is diverted through a bypass valve 552 and then combined with the expanded working fluid stream 551 to produce an termediate working fhiid stream 555. In certain exemplary embodiments, the intermediate working thud stream 555 has a temperature in the range of from about 85 to about 445 °F.

[0049] The intermediate working fluid stream 555 is then directed to one or more air- cooled condensers 587. The air-cooled condensers 557 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two air-cooled condensers 557 in series. In certain exemplary embodiments, cach of the air-cooled condensers 557 is controlled by a variable frequency drive 558. The air-cooled condensers 557 cool the intermediate working fhiid stream 5585 to form a condensed working fluid stream 559. In certain exemplary embodiments, the condensed working {fuid streama 559 has a temperature in the range of from about 80 to about 130 °F. The condensed working fluid stream 559 is then directed to a pump 560. The pump 560 is a part of the organic Rankine cycle. In certain exemplary embodiments, the pump 560 is controlled by a variable frequency drive 561. The pump 560 returns the condensed working fluid stream 559 to a higher pressure to produce the working fluid stream 512 that is directed to the heater 513. [00507 FIG. 6 shows a direct heat recovery system 600 according fo another exemplary embodiment. The heat recovery system 600 is the same as that described above with regard to heat recovery system 500, except as specifically stated below. For the sake of brevity, the simularifics will not be repeated heremmbelow. Referring now to FIG. 6, the mtermediate working {hid stream 555 is then directed to one or more water-cooled condensers 657. The water-cooled condensers 657 are a part of the organic Rankine cyele.

In certain exemplary embodiments, the organic Rankine cycle meludes two water-cooled condensers 657 in series. The water-cooled condensers 657 cool the intermediate working fhuid stream 555 to form a condensed working fhud stream 659. In certain exemplary embodiments, the condensed working fluid stream 659 has a teroperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 639 is then directed to the pump 360 and is returned to a higher pressure to produce the working fluid stream S12 that is directed to the heater 513. [00511 FIG. 7 shows an indirect heat recovery system 700 for utilization of a flue gas sirearn 711. The {flue gas strearn 711 is the same as that described above with regard to flue gas stream 511, and for the sake of brevity, the similarities will not be repeated hereinbelow.

Referring now to FIG. 7, the flue gas stream 711 is utilized fo heat a working {hid stream 712 na heater 713. The flue gas stream 711 thermally contacts the working uid stream 712 and transfers heat to the working hid stream 712. Soitable examples of the working fluid stream 712 inchide, but are not Hmited to, water, glycols, therminol fluids, alkanes, alkenes,

chlorofluorocarbons, hydrofluorocarbeons, carbon dioxide (CO2), refrigerants, and mixtures of other hydrocarbon components. The flue gas strearn 711 and the portion 712a of the working thud stream 712 enter the heater 713 to produce a heated working fluid stream 714 and a reduced heat ue gas stream 715. The heater 713 can be integrated mito the convection section of a fired heater 702. In certain exemplary embodiments, the portion 712a of the working fluid stream 712 has a temperature in the range of from about 85 to about 160 °F. In certain exeroplary embodiments, the heated working fluid stream 714 bas a temperature in the range of from about 165 to about 455 °F. In certain exemplary embodiments, the reduced heat flue gas stream 715 has a temperature in the range of from about 300 to about 750 °F.

The reduced beat flue gas stream 715 can then be vented to the atmosphere. In certain exemplary embodiments, a portion 712b of the working {luid stream 712 is diverted through a bypass valve 717 and then combined with the heated working fluid stream 714 to produce a working fluid stream 718. In certain exemplary embodiments, the working fluid stream 718 has a temperature in the range of from about 165 to about 455 °F. In certain exemplary embodiments, the working fluid stream 712 1s entirely directed through the heater 713.

[0052] A portion 718a of the working fluid stream 718 enters a heater 735 to heat a working fluid stream 736 1o produce a heated working fluid stream 737 and a reduced heat working fluid stream 738. The portion 718a of the working fluid stream 718 thermally contacts the working fluid stream 736 and transfers heat to the working {hid stream 736. In certain exeropiary embodiments, the working fluid stream 736 includes any working fluid suitable for use m an organic Rankine cycle. In certain exemplary embodiments, the working fhad stream 736 has a temperature in the range of from about 80 to about 150 °F. In certain exemplary embodiments, the heated working fluid stream 737 has a temperature in the range of from about 160 to about 450 °F. in certain exemplary embodiments, the heated working fluid stream 737 is vaporized. In certain exemplary embodiments, the heated working fluid stream 737 1s vaporized within a supercritical process. In certain exemplary embodiments, the heated working fluid stream 737 is superheated. In certain exemplary embodiments, the reduced heat working fluid stream 7328 has a teoperature in the range of from about 85 to about 155 °F. In certain embodiments, a portion 718b of the working fluid stream 718 is diverted through a bypass valve 739 and then combined with the reduced heat working thud stream 738 {o produce an intermediate working fluid stream 740. In certain exemplary embodiments, the intermediate working fluid stream 740 has a temperature in the range of from about 85 fo about 160 °F. The intermediate working fTuid stream 740 is directed to a pump 742. In certain exemplary embodiments, the pump 742 is controlled by a variable frequency drive 743. The pump 742 returns the mtermediate working fluid stream 740 to produce the working fluid stream 712 that enters the heater 713.

[0053] At least a portion 737a of the heated working fluid stream 737 is then directed to a turbine-generator system 750, which is a part of the organic Rankine cycle. The portion 737a of the heated working flaid stream 737 is expanded in the turbine-generator system 750 te produce an expanded working fhud stream 751 and generate power. In certain excraplary embodiments, the expanded working fluid stream 751 has a teroperature in the range of from about 80 to about 440 °F. In certain embodiments, the turbine-generator system 750 generates electricity or clectrical power. In certain other embodiments, the turbine-generator systema 750 generates mechanical power. In certain embodiments, a portion 737b of the heated working thud stream 737 1s diverted through a bypass valve 752 and then combined with the expanded working fluid stream 751 to produce an intermediate working {fluid stream 755. In certain exemplary embodiments, the intermediate working fluid stream 755 has a temperature in the range of from about 80) to about 445 °F.

[0054] The intermediate working fluid stream 755 is then directed to one or more air- cooled condensers 757. The air-cooled condensers 757 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two air-cooled condensers 757 in series. In certain exemplary embodiments, each of the air-cooled condensers 757 1s controlled by a variable frequency drive 758. The air-cooled condensers 757 cool the intermediate working fluid stream 755 to form a condensed working {hud stream 75%. In certain cxemplary embodiments, the condensed working hud stream 759 has a temperature in the range of from about 80 to about 150 °F. The condensed working thud stream 759 is then directed to a pump 760. The pump 760 is a part of the organic Rankine cycle. In certain oxemplary embodiments, the pump 760 is controlled by a variable frequency drive 761. The pump 760 returns the condensed working fluid stream 759 to a higher pressure to produce the working fluid stream 736 that 1s directed to the heater 7335,

[355] FIG. 8 shows an indirect heat recovery system 800 according to another exemplary embodiment. The heat recovery system 800 is the same as that described above with regard to heat recovery system 700, except as specifically stated below. For the sake of brevity, the similarities will not be repeated heremmbelow. Referring now to FIG. §, the intermediate working fluid siream 755 is directed to one or more water-cooled condensers 857. The water-cooled condensers 257 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two water-cooled condensers 857 in series. The water-cooled condensers 857 cool the intermediate working fluid stream

755 to form a condensed working fluid stream 859. In certain exemplary embodiments, the condensed working fluid stream 859 has a temperature in the range of from about 0 to about 150 °F. The condensed working fhuid stream 859 is then directed to the pump 760 and is returned to a higher pressure to produce the working fluid stream 736 that is directed o the heater 735.

[356] Referring now to FIG. 9, a direct heat recovery system 900 for utilizing a waste heat by-product stream 901 from a steam generator 802 is shown, Generally, the steam generator 902 1s used wherever a source of steam is required. In certain embodiments, a fuel stream 905 and an air stream 906 enter a burner section 902a of the steam generator 992 and heat a water stream 903 to produce a steam stream 907 and the waste heat by-product stream

S01. In certain exemplary embodiments, the waste heat by-product stream 901i has a temperature in the range of from about 400 to about 1000 °F.

[57] In certain exemplary embodiments, the waste heat by-product stream 901 is directed to a diverter valve 208 and can be separated into an exhaust stream 209 and a discharge stream 910. The discharge stream 910 can be directed to a bypass stack 911 and then discharged to the atmosphere. A portion 909a of the exhaust stream 909 can be utilized te heat a working fluid stream 912. The portion 209a of the exhaust stream 909 thermally contacts the working fluid stream 912 and transfers heat to the working {hid stream 912. In certain exemplary embodiments, the working {hud stream 912 clades any working fluid suitable for use in an organic Rankine cycle. The portion 9093 of the exhaust stream 909 and the working fluid stream 9172 enter a heater 213 to produce a heated working fluid stream 914 and a reduced heat exhaust stream 915. The heater 913 is a part of the organic Rankine cycle.

In certain exemplary embodiments, the working fluid stream 912 has a temperatare in the range of from about 80 fo about 150 °F. Tn certain exemplary crobodiments, the heated working hud stream 914 has a temperature in the range of from about 160 to about 450 °F.

In certain excroplary embodiments, the heated working fluid stream 914 is vaporized. In certain exemplary embodiments, the heated working fluid stream 914 is vaporized within a supercritical process. In certain exemplary embodiments, the heated working fluid stream 814 is superheated. In certain exemplary embodiments, the reduced heat exhaust stream 915 has a temperature m the range of from about 300 to about 800 °F. The reduced heat exhaust stream 915 can then be directed to a primary stack 916 and discharged to the atmosphere. In certain exemplary embodiments, the steam generator 902 and the heater 913 can be integrated mito the primary stack 916. In certain exemplary embodiments, the reduced heat exhaust stream 915 can be directed to an incinerator or a scrubber prior to being discharged to the atmosphere. In certain exemplary embodiments, a portion 9090 of the exhaust stream 909 is diverted through a bypass valve 917 and then combined with the reduced heat exhaust stream

B15 to produce an exhaust stream 918. In certain exemplary embodiments, the exhaust stream 918 has a temperature in the range of from about 300 to about 9035 °F. In certain exemplary embodiments, the exhaust stream 909 is entirely directed throagh the heater 913.

[358] At least a portion 914a of the heated working fluid stream 914 is then directed to a turbine-generator system 950 where the portion 914a of the heated working fluid stream 814 is expanded to produce an expanded working fluid stream 951 and generate power. In certain exemplary embodiments, the expanded working fluid stream 951 has a temperature in the range of from about 80 fo about 440 °F. In certain embodiments, a portion 914b of the heated working thud stream 914 1s diverted through a bypass valve 952 and then combined with the expanded working fluid stream 951 to produce an intermediate working {fluid stream 955. In certain exemplary embodiments, the intermediate working fluid stream 955 has a temperature in the range of from about 80 to about 445 °F.

[0059] The intermediate working fluid stream 955 is then directed to one or more air- cooled condensers 957. The air-cooled condensers 857 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two air-cooled condensers 957 in series. In certain exemplary embodiments, each of the air-cooled condensers 957 1s controlled by a variable frequency drive 958. The air-cooled condensers 957 cool the intermediate working fluid stream 955 to form a condensed working {hud stream 95%. In certain cxemplary embodiments, the condensed working hud stream 959 has a temperature in the range of from about 80 to about 150 °F. The condensed working thud stream 959 is then directed to a pump 960. The pump 960 is a part of the organic Rankine cycle. In certain oxemplary embodiments, the pump 960 is controlled by a variable frequency drive 961. The pump 960 returns the condensed working fluid stream 959 to a higher pressure to produce the working fluid stream 912 that 1s directed to the heater 913,

[060] FIG. 19 shows a direct heat recovery system 1000 according to another exemplary embodiment. The heat recovery system 1000 is the same as that described above with regard to heat recovery system 800, except as specifically stated below. For the sake of brevity, the similarities will not be repeated hereinbelow. Referring now to FIG. 14, the intermediate working fluid stream 955 is then directed to one or more water-cooled condensers 1057. The water-cooled condensers 1057 are a part of the organic Rankme cycle.

In certain exemplary embodiments, the organic Rankine cycle includes two water-cooled condensers 11357 in series. The water-cooled condensers 1657 cool the intermediate working fhid stream 955 to form a condensed working fluid stream 1059. In certain exemplary embodiments, the condensed working fluid stream 1059 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1059 is then directed to the pump 960 and is returned to a higher pressure to produce the working had stream 912 that is directed to the heater 913.

[0617] FIG. 11 shows an indirect heat recovery system 1100 for utilization of an exhaust stream 1109 from a steam generator 1102. The exhaust stream 1109 1s the same as that described above with regard to exhaust stream 909, and for the sake of brevity, the similaritics will not be repeated hereinbelow. A portion 110%a of the exhaust stream 1109 can he utilized to beat a working thud stream 1112. The portion 1109a of the exhaust stream 1109 thermally contacts the working hud stream 1112 and transfers heat to the working fluid stream 1112. Suitable examples of the working {Tuid stream 1112 include, but are not limited to, water, glycols, thermincl fluids, alkanes, alkenes, chlorofluorocarbons, hydrofhuorocarbons, carbon dioxide {(CO2), refrigerants, and mixtures of other hydrocarbon components. The portion 110% of the exhaust stream [109 and the working fluid stream 1112 enter a heater 1113 to produce a heated working fluid stream 1114 and a reduced heat exhaust stream 1115. In certain exeoplary embodiments, the working fluid streara 1112 has a temperature in the range of from about 85 to about 160 °F. In certain exemplary embodiments, the heated working fluid stream 1114 has a temperature in the range of from about 165 to about 455 °F. In certain excroplary embodiments, the reduced heat exhaust strearn 1115 has a teraperature in the range of from about 300 fo about 900 °F. The reduced heat exhaust stream 1115 can then be directed to a primary stack 1116 and discharged to the atmosphere. In cerfain excrplary embodiments, the steam generator 1102 and the beater 1113 can be integrated into the primary stack 1116. In certain exemplary embodiments, the reduced heat exhaust stream 1115 can be directed to an incinerator or a scrubber prior to being discharged to the atmosphere. In certain exemplary embodiments, a portion 1109b of the exhaust stream 1109 is diverted through a bypass valve 1117 and then combined with the reduced heat exhaust stream 11135 to produce an exhaust stream 1118. In certain excroplary embodiments, the exhaust stream 1118 has a temperature in the range of from about 300 to about 905 °F. In certain exemplary embodiments, the exhaust stream 1109 is entirely directed through the heater 1113.

[0062] Atl least a portion 1114a of the heated working fluid stream 1114 enters a heater 1133 to heat a working fluid stream 1136 to produce a heated working {fluid stream 1137 and a reduced heat working fluid stream 1138. The portion 11i4a of the heated working thud stream 1114 thermally contacts the working fluid stream 1136 and transfers heat to the working fluid stream 1136. In certain exemplary embodiments, the working find stream 1136 jocludes any working thud suitable for use in an organic Rankine cycle. In certain exemplary embodiments, the working thud stream 1136 has a teroperature m the range of from about 30 to about 150 °F. In certain exemplary embodiments, the heated working fluid stream 1137 has a temperature in the range of from about 160 to about 450 °F.

In certain exemplary embodiments, the heated working fluid stream 1137 48 vaporized. ln certain exemplary embodiments, the heated working fluid stream 1137 is vaporized within a supercritical process. In certain exemplary embodiments, the heated working fluid stream 1137 1s superheated. [un certain exemplary embodiments, the reduced heat working fluid stream 1138 has a temperature in the range of from about 85 to about 155 °F. In certain embodiments, a portion 1114b of the working flind stream 1114 1s diverted through a bypass valve 1139 and then combined with the reduced heat working fluid stream 1138 to produce an termediate working fluid stream 1140. In certain cxemplary ercbodiments, the mtermediate working fluid stream 1140 has a temperature in the range of from about 85 to about 160 °F. The intermediate working fluid stream 1140 is directed to a pump 1142. in certain exeroplary embodiments, the purop 1142 is controlled by a variable frequency drive 1143. The pump 1142 returns the intermediate working thud stream 1140 to produce the working [hud stream 1112 that enters the heater 1113.

[063] At least a portion 1137a of the heated working fluid stream 1137 is then directed to a turbine-generator system 1150, which is a part of the organic Rankine cycle.

The portion 1137a of the heated working fluid stream 1137 is expanded in the turbine- generator system 1150 to produce an cxpanded working fluid stream 1151 and gencrate power. In certain excroplary embodiments, the expanded working fluid stream 1151 has a temperature in the range of from about 80 to about 440 °F. In certain embodiments, the tarbine-generator system 1150 generates electricity or electrical power. In certain other embodiments, the turbine-generator system 1150 generates mechanical power. In certain embodiments, a portion 1137b of the heated working fluid stream 1137 is diverted through a bypass valve [152 and then combined with the expanded working fhad stream 1151 to produce an intermediate working fluid stream 1155. In certain exemplary embodiments, the intermediate working fluid streams 1153 has a temperature in the range of from about 80 to about 445 °F,

[3064] The intermediate working ffuid stream 1155 1s then directed to one or more air-cooled condensers 1157. The air-cooled condensers 1157 are a part of the organic

Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two air-cooled condensers 1157 in series. In certain exemplary embodiments, cach of the air- cooled condensers 1157 is controlled by a variable frequency drive 1158. The air-cooled condensers 1157 cool the miermediate working fluid stream 1135 to form a condensed working {hid stream 11359. In certain exemplary embodiments, the condensed working fluid stream 1159 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1159 is then directed to a pump 1160. The pump 1160 is a part of the organic Rankine cycle. In certain exemplary embodiments, the pump 1160 is controlled by a variable frequency drive 1161. The pump 1160 returns the condensed working {hid stream 1159 to a higher pressure to produce the working fluid stream 1136 that is directed to the heater 1135.

[065] FIG. 12 shows an indirect heat recovery system 1200 according to another exemplary embodiment. The heat recovery system 1200 is the same as that described above with regard fo heat recovery systern 1100, except as specifically stated below. For the sake of brevity, the sinularities will not be repeated herembelow. Referring now to FIG. 12, the intermediate working fluid stream 1155 is directed to one or more water-cooled condensers 1257. The water-cooled condensers 1257 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two water-cooled condensers 1257 in series. The water-cooled condensers 1257 cool the intermediate working {hid stream 1155 to form a condensed working {fluid stream 1259. In certain exemplary embodiments, the condensed working fluid stream 1259 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1259 is then directed to the pump 1160 and is returned to a higher pressure to produce the working fluid stream 1136 that is directed to the heater 1135.

[066] Referring now to FIG. 13, a direct heat recovery system 1300 for utilizing a waste heat by-product stream 1301 from a gas turbine 1302 is shown. In certain alternative embodiments, the gas turbine is replaced with a diesel generator (not shown}. In certain embodiments, a fuel stream 1305 and an air stream 1306 enter the gas nwbine 1302 and is combusted to produce energy and the waste heat by-product stream 1301. In certam exemplary embodiments, the waste heat by-product stream 1301 has a temperature in the range of from about 450 to about 1400 °F.

[067] In certain exemplary embodiments, the waste heat by-product stream 1301 is directed to a diverter valve 1308 and can be separated into an exhaust stream 1309 and a discharge strearn 1318. The discharge stream 1310 can be directed to a bypass stack 1311 and then discharged to the atmosphere. A portion 1309a of the exhaust stream 1309 can be utiized to heat a working fluid stream 1312. The portion 1309a of the exhaust stream 1309 thermally contacts the working fluid stream 1317 and transfers heat to the working fluid stream 1312. In certain exemplary embodiments, the working fluid strearn 1312 includes any working {hid suitable for use in an organic Rankine cycle. The portion 1309a of the exhaust stream 1309 and the working fluid stream 1312 enter a heater 1313 to produce a heated working fluid stream 1314 and a reduced heat exhaust stream 1315. The heater 1313 1s a part of the organic Rankine cycle. In certain exemplary embodiments, the working thud stream 1312 has a temperature in the range of from about 80 to about 150 °F. In certain exemplary embodiments, the heated working fluid strearn 1314 has a temperature io the range of from about 160 to about 430 °F. fn certain exemplary embodiments, the heated working fluid stream 1314 1s vaporized. In certain exemplary embodiments, the heated working fluid stream 1314 is vaporized within a supercritical process. In certain exemplary embodiments, the heated working fluid stream 1314 1s superheated. In certain exemplary embodiments, the reduced heat exhaust stream 1315 has a temperature to the range of from about 250 to about 1000 °F. The reduced heat exhaust stream 1313 can then be directed fo a primary stack 1316 and discharged to the atmosphere. In certain exemplary embodiments, the reduced heat exhaust stream 1315 can be directed to an incinerator or a scrubber prior to being discharged to the atmosphere. In certain exemplary embodiments, a portion 1309b of the exhaust stream 130% is diverted through a bypass valve 1317 and then combined with the reduced heat exhaust stream 13135 to produce an exhaust stream 1318. In certain exemplary embodiments, the exhaust stream 1318 has a temperature in the range of from about 250 to about 1100 °F.

In certain exemplary embodiments, the exhaust stream 1309 is entirely directed through the heater 1313,

[3068] Atl least a portion 1314a of the heated working fluid stream 1314 is then directed to a turbine-generator system 1350 where the portion 1314a of the heated working fluid stream 1314 is expanded to produce an expanded working fluid stream 1351 and generate power. fo certain exeraplary embodiments, the expanded working fluid stream 1351 has a teroperature tu the range of from about 80 to about 440 °F. In certain embodiments, a portion 1314b of the heated working fluid stream 1314 is diverted through a bypass valve 1352 and then combined with the expanded working fluid stream 1351 to produce an miermediate working fluid stream 1355. In certam exemplary embodiments, the intermediate working {fluid stream 1355 has a temperature in the range of from about 80 to about 445 °F.

[0069] The intermediate working thud stream 13535 is then directed to one or more air-cooled condensers 1357. The air-cooled condensers 1357 are a part of the organic

Rankine cycle. In certain exeraplary embodiments, the organic Rankine cycle includes two air-cooled condensers 1357 in series. In certain exeroplary embodiments, each of the air- cooled condensers 1357 is controlled by a variable frequency drive 1358. The air-cooled condensers 1357 cool the intermediate working fluid stream 1355 to form a condensed working fluid strearo 135%. In certain exemplary embodiments, the condensed working fluid stream 1359 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1359 is then directed to a pump 1360. The pump 1360 is a part of the organic Rankine cycle. To certain exemplary cobodiments, the purap 1360 is controlled by a variable frequency drive 1361. The pump 1360 returns the condensed working fluid stream 135% to a higher pressure to produce the working fluid stream 1312 that 1s directed to the heater 1313.

[0070] FIG. 14 shows a direct heat recovery systern 1400 according to another exemplary embodiment. The heat recovery system 1400 1s the same as that described above with regard to heat recovery system 13{H), except as specifically stated below. For the sake of brevity, the sirailarities will not be repeated herembelow. Referring now to FIG. 14, the miermediate working fluid stream 1355 4s then directed to one or more water-cooled condensers 1457. The water-cooled condensers 1457 are a part of the organic Rankine cycle.

In certain exemplary embodiments, the organic Rankine cycle mcludes two water-cooled condensers 1457 in series. The water-cooled condensers 1457 cool the intermediate working fhad stream 1355 to form a condensed working fluid stream [459 In certain exemplary embodiments, the condensed working fluid stream 1459 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1459 is then directed to the purop 1360 and is returned to a higher pressure to produce the working fluid stream 1312 that is directed to the heater 1313.

[071] FIG. 15 shows an indirect heat recovery system 1500 for utilization of an exhaust strearn 1509. The exhaust stream 1509 is the same as that described above with regard to exhaust stream 1309, and for the sake of brevity, the similarities will not be repeated hereinbelow. A portion 150%a of the exhaust stream 1509 can be utilized to heat a working fluid stream 1512. The portion 1509a of the exhaust stream 1509 thermally contacts the working fluid stream 1512 and transfers heat to the working fluid stream 1512. Suitable examples of the working fluid stream 1512 mchude, but are not hmited to, water, glycols, thermino! fluids, alkanes, alkenes, chlorofhuorocarbons, hydrofluorocarbons, carbon dioxide

{CO}, refrigerants, and mixtures of other hydrocarbon components. The portion [50% of the exhaust stream 1509 and the working fluid stream 1512 enter a heater 1513 to produce a heated working fluid stream 1514 and a reduced heat exhaust stream 1515. In certain exemplary embodiments, the working fluid stream 1512 has a temperature in the range of from about 85 to about 160 °F. In certain exemplary embodiments, the heated working fluid stream 1514 has a temperature in the range of from about 165 to about 455 °F. In certain exemplary cobodiments, the reduced heat exhaust strearn 1515 has a teowperature in the range of from about 250 lo about 1000 °F. The reduced heat exhaust stream 1515 can then be directed to a primary stack 1516 and discharged to the atmosphere. In certain exemplary embodiments, the reduced heat exhaust stream 1515 can be directed to an incinerator or a scrubber prior to being discharged to the atmosphere. In certain exemplary embodiments, a portion 1509 of the exhaust stream 1509 is diverted through a bypass valve 1517 and then combined with the reduced heat exhaust stream 1515 to produce an exhaust stream 1518. In certain exemplary embodiments, the exhaust stream 1518 has a temperature in the range of from about 250 to about 1100 °F. In certain exemplary embodiments, the exhaust stream 1509 is entirely directed through the heater 1513.

[0072] Atl least a portion 1514a of the heated working fluid stream 1514 enters a heater 15335 to heat a working fluid stream 1536 to produce a heated working fluid stream 1537 and a reduced heat working fluid stream 1538. The portion 15i4a of the heated working fluid stream 1514 thermally contacts the working {luid stream 1536 and transfers heat to the working fluid stream 1536. In certain exemplary embodiments, the working thud stream 1536 includes any working fluid scitable for use in an organic Rankine cycle. In certain exemplary embodiments, the working fluid stream 1536 has a temperature in the range of from about 80 fo about 150 °F. Tn certain exemplary crobodiments, the heated working (hud stream [537 has a temperature in the range of from about 160 to about 450 °F.

In certain exemplary embodiments, the heated working {huid stream 1537 4s vaporized. In certain exemplary embodiments, the heated working fluid stream 1537 is vaporized within a supercritical process. In certain exemplary embodiments, the heated working fluid stream 1537 ia superheated. In certain exemplary embodiments, the reduced heat workmg thud stream 1538 has a temperabire in the range of from about 85 to about 155 °F. In certain embodiments, a portion 1514b of the working fluid stream 1514 is diverted through a bypass valve 1539 and then combined with the reduced heat workimg fluid stream 1538 to produce an intermediate working fluid stream 1540. In certain exemplary embodiments, the intermediate working {hud stream 1540 has a temperature in the range of from about 85 {o about 160 °F. The intermediate working {hud stream 1540 is directed to a pump 1542. In certain exemplary embodiments, the pump 1542 is conirolied by a variable frequency drive 1543. The pump 1542 returns the intermediate working thud stream 1540 to produce the working {fluid stream 1512 that enters the heater 1513.

[073] At east a portion 1537a of the heated working fluid stream 1537 is then directed to a turbine-generator system 1550, which is a part of the organic Rankine cycle.

The portion 1537a of the heated working fluid stream 1537 is expanded in the turbine- generaior system 1550 to produce an expanded working floid stream 1551 and generate power. In certain excraplary embodiments, the expanded working fluid stream 1551 has a temperature in the range of from about 80 to about 440 °F. In certain embodiments, the tarbine-generator system 1550 generates electricity or electrical power. In certain other embodiments, the turbine-generator system 1550 generates mechanical power. In certain embodiments, a portion 1537b of the heated working fluid stream 1537 is diverted through a bypass valve 1552 and then combined with the expanded working fluid stream 1351 to produce an intermediate working fluid stream 1555. In certain exemplary embodiments, the intermediate working fluid stream 1553 has a temperature in the range of from about 80 to about 445 °F.

[3074] The intermediate working fluid stream 1555 1s then directed to one or more air-cooled condensers 1557. The air-copled condensers 1557 are a part of the organic

Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two air-cooled condensers 1557 in series. In certain exeoplary embodiments, each of the air- cooled condensers 1557 is controlled by a variable frequency drive 1558. The air-cooled condensers 1557 cool the intermediate working fluid stream 1555 fo form a condensed working fluid stream 1559. To certain exemplary embodiments, the condensed working fluid stream 1559 has a temperature in the range of {rom about 80 to about 150 °F. The condensed working fluid stream 1559 is then directed to a pump 1560. The pump 1560 is a part of the organic Rankine cycle, In certain exemplary embodiments, the pump 1560 is conirolled by a variable frequency drive 1561. The pump 1560 returns the condensed working thud stream 1559 to a higher pressure to produce the working fluid stream 1536 that is directed to the heater 1535. [00751 FIG. 16 shows an indirect heat recovery system 1600 according to another exemplary embodiment. The heat recovery systern 1600 is the same as that described above with regard to heat recovery system 1500, except as specifically stated below. For the sake of brevity, the similarities wil not be repeated hereinbelow. Referring now to FIG. 16, the mtermediate working {laid stream [555 is directed to one or more water-cooled condensers 1657. The water-cooled condensers 1657 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two water-cooled condensers 1657 in series. The water-cooled condensers 1657 cool the mtermediate working fhid stream 1555 to form a condensed working {luid stream 1659. In certain exemplary embodiments, the condensed working fluid stream 1659 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1659 1s then directed to the pump 1560 and is returned to a higher pressure to produce the working fluid stream 1536 that is directed to the heater 1535.

[0076] Referring now to FIG. 17, a direct heat recovery system 1700 for utilizing a heat by-product stream 1701 from a process column 1702 is shown. Suitable examples of process columms inclade, but are not Hmited to, distiliation columns and strippers. In certain exemplary embodiments, the heat by-product stream 1701 has a temperature in the range of from about 170 to about 700 °F. A portion 17014 of the heat by-product stream 1701 can be utilized to heat a working thud stream 1712. The portion 1701a of the heat by-product stream 1701 thermally contacts the working fluid stream 1712 and transfers heat to the working fluid stream 1712. In certain excoplary embodiments, the working thud stream 1712 mneludes any working thud suitable for use in an organic Rankine cycle. The portion 1701a of the heat by-product stream 1701 and the working fluid stream 1712 enter a heater 1713 to produce a heated working fluid stream 1714 and a reduced heat exhaust stream 1715.

The heater 1713 is a part of the organic Rankine cycle. In certain exemplary embodiments, the working fluid stream 1712 has a temperatare in the range of from about 80 to about 150 °F. In certain exemplary embodiments, the heated working fluid stream 1714 has a temperature in the range of from about 160 fo about 450 °F. lon certain exemplary embodiments, the heated working fluid stream 1714 is vaporized. In certain exemplary embodiments, the heated working fluid stream 1714 is vaporized within a supercritical process. In certain exemplary embodiments, the heated working fluid stream 1714 is superheated. In certain exemplary erabodiments, the reduced heat exhaust stream 1715 has a temperature in the range of from about 90 to about 5300 °F. The reduced heat exhaust stream 1715 can then be vented to the atmosphere. In certain exemplary embodiments, a portion 1701b of the heat by-product stream 1701 is diverted through a bypass valve 1717 and then combined with the reduced heat exhaust stream 1715 to produce an exhaust stream 1718. In certain exemplary embodiments, the exhaust stream 1718 has a temperature in the range of from about 90 to aboul 510 °F. In certain exemplary embodiments, the heat by-product stream 1701 is entirely directed through the heater 1713.

[0077] Atl least a portion 1714a of the heated working fluid stream 1714 is then directed to a turbine-generator aystern 1750 where the portion 1714s of the heated working fluid stream 1714 1s expanded to produce an expanded working fluid stream 1751 and generate power. In certain exerapiary embodiments, the expanded working fiuid stream 1751 has a teroperature in the range of from about 80 to about 440 °F. In certain embodiments, a portion 1714b of the heated working fluid stream 1714 is diverted through a bypass valve 1752 and then combined with the expanded working fluid stream 1751 to produce an mermediate working fluid stream 1755. In certain exemplary embodiments, the intermediate working {luid stream 1755 has a temperature in the range of from about 30 to about 455 °F.

[3078] The intermediate working fluid stream 1755 1s then directed to one or more air-cooled condensers 1757. The air-cooled condensers 1757 are a part of the organic

Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle meludes two air-cooled condensers 1757 in series. In certam exemplary embodiments, each of the air- cooled condensers 1757 is controlled by a variable frequency drive 1758. The air-cooled condensers 1757 cool the intermediate working fluid stream 1755 fo forma a condensed working (hud stream 1759. Tn certain exemplary embodiments, the condensed working fluid stream 1759 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1759 is then directed to a pump 1760. The pump 1760 is a part of the organic Rankine cycle. In certain exemplary erobodiments, the pump 1760 is controlled by a variable frequency drive 1761. The pump 1760 returns the condensed working {had stream 1759 to a higher pressure to produce the working fluid stream 1712 that is directed to the heater 1713,

[0079] FIG. 18 shows a direct heal recovery system 1800 according to another exemplary embodiment. The heat recovery system 1800 is the same as that described above with regard to heat recovery system 1700, except as specifically stated below. For the sake of brevity, the similarities will not be repeated herembelow. Referring now to FIG. 18, the mtermediate working {hid stream 1755 is then directed to one or more water-cooled condensers 1857. The water-cooled condensers 1857 are a part of the organic Rankine cycle.

In certain excroplary embodiments, the organic Rankine cycle includes two water-cooled condensers 1857 mn series. The water-cooled condensers 1857 cool the intermediate working fluid stream 1755 to form a condensed working {hid stream 1359. In certain exemplary embodiments, the condensed working fluid stream 1859 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1859 is then directed to the pump 1760 and is returned to a higher pressure to produce the working fluid stream 1712 that is directed to the heater 1713.

[0080] FIG. 19 shows an indirect heat recovery system 1800 for uulization of heat by- product stream 1901. The heat by-product stream 1901 is the same as that described above with regard to heat by-product stream 1701, and for the sake of brevity, the similarities will not be repeated hereinbelow. A portion 1901a of the heat by-product stream 1901 can be utilized to heat a working {hud stream 1912. The portion 1901a of the heat by-product stream 1901 thermally contacts the working fluid stream 1912 and transfers heat to the working fluid stream 1912. Suitable examples of the working fluid stream 1912 include, but are not hmited to, water, glycols, therminol fluids, alkanes, alkenes, chloroflusrocarbons, hydrofluorccarbons, carbon dioxide {CO2), refrigerants, and mixtures of other hydrocarbon components. The portion 1901s of the heat by-product stream 1901 and the working fluid strearn 1912 enter a heater 1913 to produce a heated working fhuid stream 1914 and a reduced heat exhaust stream 1915. In certain exemplary embodiments, the working fluid stream 1912 has a teroperature in the range of from about 85 to about 160 °F. In certain exemplary embodiments, the heated working fluid strearn 1914 has a temperature io the range of from about 165 to about 455 °F. In certam exemplary embodiments, the reduced heat exhaust stream 1915 has a temperature in the range of from about 90 to about 560 °F. The reduced heat exhaust stream 1915 can then be vented to the atmosphere. In certain excraplary embodiments, a portion 1901b of the heat by-product stream 1901 is diverted through a bypass valve 1917 and then combined with the reduced heat exhaust stream 1913 to prodace an exhaust stream 1918. In certain exeraplary embodiments, the exhaust stream 1918 has a temperature in the range of from about 90 to about 510 °F. In certain exemplary embodiments, the heat by-product strearn 1901 1s entirely directed through the heater 1913.

[081] At least a portion 1914a of the heated working fluid stream 1914 enters a heater 1935 to heat a working fluid stream 1936 to produce a heated working {hid stream 1937 and a reduced heat working fluid stream 1938. The portion 1914a of the heated working thud stream 1914 thermally contacts the working fluid stream 1936 and transfers heat to the working fluid stream 1936. In certain exemplary embodiments, the working {hud stream 1936 includes any working fluid suitable for use in an organic Rankine cycle. In certain exemplary embodiments, the working thud stream 1936 has a teroperature m the range of from about 30 to about 150 °F. In certain exemplary embodiments, the heated working fluid stream 1937 has a temperature in the range of from about 160 to about 450 °F.

In certain exemplary embodiments, the heated working fluid stream 1937 is vaporized. In certain exemplary embodiments, the heated working fluid stream 1937 is vaporized within a supercritical process. In certain exemplary embodiments, the heated working thud stream 1937 1s superheated. In certain exemplary embodiments, the reduced heat working fluid stream 1938 has a temperature in the range of from about 85 to about 155 °F. In certain embodiments, a portion 1914b of the working fluid stream 1914 is diverted through a bypass valve 1939 and then combined with the reduced heat working thud stream 1938 to produce an termediate working fluid stream 1940. In certain exemplary embodiments, the intermediate working fluid stream 1940 has a teroperature in the range of from about 85 to about 160 °F. The intermediate working fluid stream 1940 is directed to a pump 1942. in certain exemplary embodiments, the pump 1942 is controlled by a variable frequency drive 1943. The pump 1942 returns the intermediate working thud stream 1940 to produce the working fluid stream 1912 that enters the heater 1913.

[0082] At least a portion 1937a of the heated working fluid stream 1937 is then directed to a turbine-generator system 1950, which is a part of the organic Rankine cycle.

The portion 1937a of the heated working fluid stream 1937 is expanded in the turbine- generator system 1950 to produce an expanded working fluid stream 1951 and generate power. In certain exeroplary embodiments, the expanded working fluid stream 1951 has a temperature in the range of from about 80 {0 about 440 °F. In certain embodiments, the turbine-generator system 1950 generates electricity or electrical power. In certain other embodiments, the turbine-generator system 1950 generates mechanical power. In certain embodiments, a portion 1937b of the heated working fluid stream 1937 is diverted through a bypass valve 1952 and then combined with the expanded working fhud stream 1951 to produce an intermediate working fluid stream 1955. In certain exeroplary embodiments, the mitermediate working fluid stream 1955 has a temperature in the range of from about 80 to about 445 °F.

[0083] The intermediate working ffuid stream 1955 is then directed to one or more air-cooled condensers 1957. The air-cooled condensers 1957 are a part of the organic

Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle meludes two air-cooled condensers 1957 in series. In certain exemplary embodiments, cach of the air- cooled condensers 1957 is controlled by a variable frequency drive 1958. The air-cooled condensers 1957 cool the intermediate working fluid stream 1955 to form a condensed working {hid stream 1959. In certain exemplary embodiments, the condensed working fluid stream 1959 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 1959 is then directed to a pump 1960. The pomp 1960 is a part of the organic Rankine cycle. In certain exemplary embodiments, the pump 1960 is controlled by a variable frequency drive 1961. The pump 1960 returns the condensed working fluid stream 1959 to a higher pressure to produce the working fluid stream 1936 that 1s directed to the heater 1935.

[0084] FIG, 20 shows an indirect heat recovery system 2000 according to another exemplary embodiment. The heat recovery system 2000 is the same as that described above with regard to heat recovery systern 1900, except as specifically stated below. For the sake of brevity, the similarities will not be repeated hereinbelow. Referring now to FIG. 20, the itermediate working fluid stream 19355 is directed to one or more water-cooled condensers 2057. The water-cooled condensers 2057 are a part of the organic Rankine cycle. In certain exemplary embodiments, the organic Rankine cycle includes two water-cooled condensers 2057 in series. The water-cooled condensers 2057 cool the intermediate working fhud stream 1955 to form a condensed working fluid stream 2059. In certain exemplary embodiments, the condensed working thud stream 20359 has a temperature in the range of from about 80 to about 150 °F. The condensed working fluid stream 2059 is then directed to the pump 1960 and is returned to a higher pressure to produce the working fluid stream 1936 that is directed to the heater 1935.

[085] The present invention may employ any number of working fhids in the organic Rankine cycle. Suitable examples of working fluids for use in the organic Rankine cycle include, but are not limited to, aromounia (NH3), bromine (B12), carbon tetrachloride {(CC14), ethyl alcohol or ethanol (CH3CH2OH, CZH6(), furan {C4H4O), hexaftuorobenzene or perfluore-benzene (Co6F6), hydrazine (NZH4), methyl alcohof or methanol (CH30H), monochlorobenzene or chlorobenzene or chlovobenzol or benzine chloride (C6HSCL), n- pentane or normal pentane (nC3), i-hexane or isohexane (CS), pyridene or azabenzene (C3HS5N), refrigerant 11 or freon 11 or CFC-11 or R-11 or trichlorofluoromethane (CC13F), refrigerant 12 or freon 12 or R-12 or dichlorodifluoromethane (CCi2F2), refrigerant 21 or freon 21 or CFC-21 or R-21 (CHCI2F), refrigerant 30 or freon 30 or CFC-30 or R-30 or dichloromethane or methylene chloride or methylene dichlonde (CH2C12), refrigerant 115 or freon 115 or CFC-115 or R-113 or chloro-pentafluorocthane or monochioropentaftuoroethane, refrigerant 123 or freon 123 or HCFC-123 or R-123 or 2.2 dichloro-1,1,1-trifluoroethane, refrigerant 123a or freon 123a or HCFC-123a or R-123a or 1,2-dichloro-1,1,2-trifluorcethane, refrigerant 12301 or freon 12361 or HCFC-123b1 or R- 123b} or halothane or Z-bromo-2-chloro-1,1,1-trifluorocthane, refrigerant 134A or freon

134A or HFC-134A or R-134A or 1,1,1,2-tetrafluoroethane, refrigerant 150A or freon 150A or CFC-150A or R-150A or dichloroethane or ethylene dichloride {CH3ICHC12), thiophene (C4H4S), toluene or methylbenzene or phenyhmethane or toluol (C7HR}, water (H20), carbon dioxide (CO2), and the like. In certain exemplary embodiments, the working fluid may inclode a combination of components. For example, one or more of the compounds identified above may be combined or with a hydrocarbon fluid, for example, isobutene.

However, those skilled in the art will recognize that the present invention is not limited fo any particular type of working fluid or refrigerant. Thus, the present invention should not be considered as limited to any particular working fluid unfess such limitations are clearly sot forth in the appended claims.

[3086] The present application 1s generally directed to various heat recovery systems and methods for producing electrical and/or mechanical power from a heat source. The exemplary systems may include a heat exchanger, a turbine-generator set, a condenser heat exchanger, and a pump. The present invention is advantageous over conventional heat recovery systems and methods as it utihzes heat that would otherwise be rejected to the atmosphere to produce electricity and/or mechanical power, thus increasing process efficiency

[0087] Therefore, the present mvention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. While numerous changes may be made by those skilled in the art, such changes are encompassed within the spirit of this invention as defined by the appended claims. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. it is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. The terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.

Claims

CLAIMS What 1s claimed is:

1. A process for utilizing process heat by-product from refinery operations, COTIprising: a first sub-process, a second sub-process, and a third sub-process, the first sub- process comprising the steps oft a) directing process heat by-product from a refinery operation to a first heater; b) thermally contacting in said first heater the process heat by-product with a first working thud to cool the process heat by-product to form a cooled by-product; ¢) exhausting the cooled by-product to atmosphere; the second sub-process comprising the steps off dy heating in said first heater the first working thud to form a first heated working fluid; c) directing the first heated working fiuid to a second heater; fH thermally contacting in said second heater the first heated working fhiid with a second working fluid to cool the first heated working fluid to form a first cooled working fluid; 2) passing the {irst cooled working hid through a pump to {form said first working fluid; and the third sub-process comprising the steps of: hj heating in said second heater the second working fluid to form a second heated working hud; 1} passing the second heated working thud through a twbine to form an expanded working fluid, wherein said passing of the second heated working fluid through the turbine drives a generator for production of one of electricity and mechanical power; i} passing the expanded working fluid through at least one heat exchanger to form a condensed working fluid; and k} passing the condensed working fluid through at least one puny to form said second working fhuid; wherein the first and second sub-processes are linked via the first heater, wherein the second and third sub-processes are hinked via the second heater, and wherein first, second, and third sub-processes occur simultaneously. a2

2. The process of claim 1, wherein the at least one heat exchanger is selected from: the group consisting of air-cooled condensers and water-cooled condensers.

3. The process of claim 1, wherein said process heat by-product comprises flue gas or waste heat from refinery operations.

4, The process of claim 1, wherein said process heat by-product comprises flue gas from a fluid catalytic cracking unit.

5. The process of claim 1, wherein said process heat by-product comprises heat by-product generated by directing flue gas from a {had catalytic cracking regenerator to a waste heat 2 g Y gg stcam generator for generating steam, passing said flue gas through an electrostatic precipitator to remove catalyst fines present in the fue gas, and recovering the process heat by-prodoct from the flue gas exiting the electrostatic precipitator.

6. The process of claim 1, wherein said process heat by-product comprises heat by-product generated by directing a flue gas {rom a fluid catalytic cracking regenerator to a botler, wherein the flue gas comprises carbon monoxide, combusting the carbon monexide in the boiler to generate steam, passing the flue gas through an electrostatic precipitator to remove catalyst fines present m the flue gas, and recovering the process heat by-product from the flue gas exiting the electrostatic precipitator.

7. The process of claim 1, wherein said process heat by-product comprises recovered heat from a high temperature reactor.

&. The process of claim 7, wherein the high temperature reactor is a fired heater or an meinerator.

9. The process of claim 7, where said beater is integral to a convection section of the high temperature reactor.

10. The process of claim 1, wherein the second working {hid is selected from the group consisting of organic working fluids and refrigeranis.

11. The process of claim 1, wherein the step of heating the second working fluid to form the second heated working fluid comprises vaporizing the second working fluid.

12. The process of claim 1, wherein the step of heating the second working hud to form the second heated working fluid comprises vaporizing the second working fluid within a supercritical process.

13. A process for utilizing waste heat by-product, comprising: a first sub-process, a second sub-process, and a third sub-process, the first sub- process comprising the steps of a) directing waste heat by-product to a first heater; b) thermally contacting in said first heater the waste heat by-product with a first working fluid to cool the waste heat by-product to form a cooled by-product; ¢) exhausting the cooled by-product; the second sub-process comprising the steps of! d) heating in said frst heater the first working fluid to form a first heated working fluid; ¢} directing the first heated working fluid to a second heater; f thermally contacting in said second heater the first heated working fluid with a second working thud to cool the first heated working fhod to form a first cooled working fluid; 2) passing the first cooled working fluid through at least one pump to form said first working thud; and the third sub-process comprising the steps off hy heating mw said second heater the second working fluid to form a second heated working fluid; 1} passing the second heated working fluid through a turbine to form an expanded working fluid, wherein said passing of the second heated working fluid through the turbine that drives a generator for production of one of electricity and mechanical power; i} passing the expanded working thud through at least one heat exchanger to form a condensed working fluid; and k) passing the condensed working fluid through a pomp to form said second working fluid: wherein the first and second sub-processes are linked via the first heater, wherein the second and third sub-processes are linked via the sccond heater, and wherein first, second, and third sub-processes occur simultaneously.

14. The process of claim 13, wherein the at least one heat exchanger is selected from: the group consisting of air-cooled condensers and water-cooled condensers.

15. The process of claim 13, further comprising the step of directing the cooled by-product to one of an incinerator, a scrubber, and a stack prior to exhausting the cooled by- product to the atmosphere.

16. The process of claim 13, wherein said waste heat by-product comprises waste heat from a steam generator.

17. The process of claim 13, wherein said waste heat by-product is generated by directing water into a steam generator, heating the water with a heated air stream to form steam and the waste heat by-product,

18. The process of claim 17, further comprising the step of diverting a portion of the waste heat by-product through a diverter valve for discharging to atmosphere.

19. The process of claim 13, wherein said waste heat by-product comprises waste heat from a gas turbine.

20. The process of clam 13, wherein said waste heat by-product is generated by directing fuel into a gas turbine, and combusting the fuel in the gas turbine to generate power and the waste heat by-product,

21. The process of claim 13, wherein the second working fluid is selected from the group consisting of organic working fluids and refrigerants,

22. The process of claim 13, wherein the step of heating the second working laid te form the second heated working fluid comprises vaporizing the second working fluid.

23. The process of claim 13, wherein the step of heating the second working fluid to form the second heated working fhud comprises vaporizing the second working fluid within a supercritical process.

24. A system for utilizing a heat by-product, comprising: an organic Rankine cycle comprising a heater, a turbine and generator, at least one heat exchanger, and a pump, wherein the at least one heat exchanger is selected from air- cooled heat exchangers and water-cooled heat exchangers; and a heat source, wherein the heat source is one selected from process heat by- products from refinery operations and waste heat by-products.